Downhole oil and gas production operations, and particularly those in multi-stage horizontal wells, require the stimulation and production of one or more zones of a hydrocarbon bearing formation. In many cases this is done by running a liner or casing string downhole, in which the liner or casing string comprises one or more downhole sleeves, including but not limited to ported sleeves or collars, at spaced intervals along the wellbore. The location of the downhole sleeves is commonly set to align with the formation zones to be stimulated or produced. The sleeves must be manipulated in order to be opened or closed as required. In some instances, this is achieved by running a bottom hole assembly, also known as an intervention tool, down through the liner or casing string, locating in the downhole sleeve to be manipulated and manipulating the sleeve by any number of means including use of mechanical force on the intervention tool, or by hydraulic pressure.
The bottom hole assembly (BHA), or intervention tool, also known by any number of other names, is typically run on a tubing string that can be coil tubing or other tubing. The intervention tool is sent down inside the liner or casing string for the purposes of locating inside and interacting with the downhole sleeve adjacent the formation zone to be treated or produced. Once located near or inside the downhole sleeve, the intervention tool typically engages against the downhole sleeve or against the liner or casing near the downhole sleeve, and then the intervention tool is either mechanically manipulated or hydraulic pressure is used to manipulate the downhole sleeve as required to stimulate the oil-bearing formation, or to produce hydrocarbons from the formation. After treatment, it may also be desirable to again manipulate the downhole sleeve. In many cases, it is also desirable to set an intervention tool in a liner or casing string or a blank pipe.
Once opened, in many cases, it is desirable to be able to further manipulate the intervention tool within the liner after opening the downhole sleeve, to then be able to re-close the downhole sleeve. It is further desirable to be able to return the intervention tool to the initial run in hole position, for ease of running the intervention tool further down the wellbore, or to pull the intervention tool out of the hole, without having the downhole sleeve unintentionally open or close. In some cases, a downhole sleeve might become stuck and not mechanically openable, in which case it may be necessary to move the intervention tool further downhole and position a perforator run on the intervention tool to perforate the liner proximal to the downhole sleeve. In other cases, it may be desirable to move the intervention tool uphole and down hole through the liner to check locations of downhole sleeves, or to open or close downhole sleeves in a non-sequential manner.
There is therefore still a need for intervention tool and sleeve systems that can run an intervention tool inside a downhole tool or inside a liner or casing string to open the downhole sleeve or set in the liner or casing, and for systems that allow for multiple positions of the intervention tool within the liner for varying purposes.